Tag Archive: Neandertals

Well, according to Ernst Mayr’s Biological Species Concept, which holds that species are “groups of actually or potentially interbreeding natural populations, which are reproductively isolated from other such groups,” the newest genetic data (see a previous post on this blog) suggest that perhaps they should be considered the same species. A nice summary of the debate is provided by Ann Gibbons in Science. While some paleoanthropologists (including our keynote speaker John Hawks, who is quoted in the piece; check out his blog post on the subject) consider Neandertals and modern humans to be the same species, others maintain that the two are distinct species because the anatomical, developmental, and behavioral differences between Neandertals and modern humans are much greater than what we see among any modern population.

Check out Gibbons’s piece and tell us what you think. Are we the same species or not (remember, it also depends on what species definition you decide to use)?

It is likely that Dr. Hawks will be addressing some of these issues in his keynote lecture (we now have a title for the talk: “Neandertime: Deciphering the Secrets of Ancient Genomes.”)

A team of researchers have scanned genes that are known to impact hair color and found that analyzing an individual’s DNA can predict their hair color with a high degree of accuracy. There are upwards of a dozen or so genes that may contribute to hair color in some way, and mutations that change a single nucleotide (Single Nucleotide Polymorphisms, or SNPs) in a gene are largely responsible for color and shade differences. From a summary in Wired Science:

To see if hair color could be predicted using 45 SNPs from 13 genes, Kayser and his team sampled DNA from 385 Polish volunteers and had dermatologists record their hair color. Their testing singled out 13 SNPs on 11 genes that could predict red and black hair colors with about 90 percent accuracy, as well as blond and brown colors with better than 80 percent accuracy.

As if you needed another excuse not to leave your DNA at a crime scene…

One of the genes examined in this study was MC1R, mutations in which have been linked specifically to red hair. Interestingly, the red hair genotype has been identified in some Neandertal individuals (although the specific mutation is different from that seen among modern humans).

Just as we are trying to digest the implications of the draft Neandertal genome (which, by the way, suggests that Neandertals contributed up to 4% of their genomes to non-African modern human populations), a new study published in Nature by David Reich (Harvard Med School) and colleagues reports the genome of an unclassified (all we have is a pinky bone and an isolated tooth) ca. 40,000-year-old hominin from Denisova Cave in southern Siberia. The genome appears distinct both from that of European Neandertals and contemporary modern humans. However, there is evidence that early modern human populations interbred with these “Denisovans” and, in fact, modern Melanesian populations (represented in the paper by genomes from Papua New Guinea and Bougainville) appear to have received approximately 4% of their genomes from this extinct group of humans.

So, taken together, these genetic data seem to indicate that modern Melanesians derive up to 8% of their genomes (4% Neandertal and 4% “Denisovan”) from now-extinct human groups. Pretty cool stuff.

Check out the summaries from Science News and Nature for more information, and our keynote speaker John Hawks’s weblog provides very detailed commentary on these exciting findings.

UPDATE 12.23.11. Dr. Hawks is also interviewed in an NPR story from Dec. 23 that summarizes the implications of these data.